The 1675 GMT-MASTER
Movement: 1565 and later 1575
Produced: From around 1959 to around 1979
Features: Hours, Minutes, Seconds, Date and 24 hour hand dual time feature.
Rolex made some blue GMTs in the 70s. Some were made for foreign military services (Italian comes to mind). I have seen blues with Peruvian Air Force markings on the caseback.
Some were also made with a Cartier dial and this one with Arabic markings on the dial.
PHOTO CREDIT AAKVIPER
I've read reports the insert you show may have some issues.